A population of the North-East Atlantic feather star Antedon bifida (Pennant) from a site in strong currents off South Devon, U.K., maintains a high level of maturity throughout its annual cycle, yet spawns only at a precise period of the year. Most individuals lose a proportion (mean: 17 %) of their pinnules from predation by the corkwing wrasse, Crenilabrus melops. An account of some aspects of predation of the crinoid by the fish is given. It is suggested that the crinoid maintains the maturity of its reproductive tissues at an unusually high level throughout the year so that the predator will take the pinnules, including the energy-rich gonads, in preference to the more vulnerable calyx. It is also suggested that a stress-response may be involved in the maintenance of continuous gametogenic activity by the crinoid, and, further, that attracting the predatory fish,to itself may help rid the crinoid's exterior of epizoics.